Question

The total surface area of a cube is 864 cm². Find its volume.

Answer 1

Let the side of the cube be 'a' cm
∴ Total surface area of a cube = 6a²
∴ 864 = 6a²   ...(Given)

a² = `(864)/(6)`
a² = 144
a = `sqrt(144)`  ...(Taking square roots on both sides)
∴ a = 12cm
Volume of a cube
= a³
= 12³
= 1728cm³
∴ Volume of the cube = 1728cm³.